Particular genetic variant known as BDNF can cause obesity

Researchers found that a single gene variation, called Brain-Derived Neurotrophic Factor (BDNF) may affect the brain’s regulation of appetite, linking it to obesity.

The study, published in the Journal Cell Reports, suggests that a lesser common version of the BDNF gene can predispose people to obesity, due to the lower production of the BDNF protein, failing to regulate the appetite.

“The BDNF gene has previously been linked to obesity, and scientists have been working for several years to understand how changes in this particular gene may predispose people to obesity,” said Jack A. Yanovski, one of the study authors and an investigator at NIH’s, according to a press release.

More people in the world are suffering from obesity than from hunger. Chicken contains 266% more fat than it did 40 years ago. Lack of sleep can cause weight gain of 2 pounds in under a week. Credit: thefatkidinside.com

Researchers believe that increasing the BDNF levels can help people with this genetic variation, stabilizing their appetite to control their weight. The human body relies on these genes to regulate functions and to avoid the disbalance that occurs when excessive energy is stored and the weight increases.

Health conditions such as strokes, diabetes and several heart diseases —all serious issues on the U.S.— are related to obesity, especially in children. Also, the study reports that the genetic variation is more frequently found in African Americans and Hispanics.

The BDNF protein, at high levels, tells the brain to feel the fullness sensation on our stomachs. The team, led by Joan C. Han from the University of Tennessee, analyzed the genetic alterations of the BDNF gene. They studied the gene in four groups of people —more than 31,000 men and women— from several clinical research studies.

Studying the brain, the scientists found the area of the gene that produced the reduction of the protein level, in the hypothalamus —an important part of the brain that controls the autonomous nervous system and the secretion of certain hormones.

“This study explains how a single genetic change in BDNF influences obesity and may affect BDNF protein levels. Finding people with specific causes of obesity may allow us to evaluate effective, more-personalized treatments.” said Mr. Yanovski.

Nevertheless, the researchers say that this genetic change it is not a “rare mutation, but a variation that occurs in the general population”. They explain that all of us have two copies —called alleles— of each gene, one coming from each parent. These alleles can variate, and one of them causes the lack of BDNF protein in our bodies.

According to statistics from the Centers for Disease Control and Prevention, more than 34.9 percent of U.S. adults are obese —78.6 million people. Another fact, related to the study, shows that obesity affects the most the non-hispanics black group (47.8 percent of obesity), followed by the hispanics group (42.5 percent of obesity).